Delivery device in sheet-fed offset rotary printing press

ABSTRACT

A delivery device in a sheet-fed offset rotary printing press includes a plurality of suction units, at least one discharge unit, at least one support member, and an intake source, air exhaust system, and switching device. The plurality of suction units are arranged above a pile board on an upstream sheet convey direction side below a sheet under conveyance in a widthwise direction of the sheet, and draw by suction the sheet under conveyance in slidable contact with it. At least one discharge unit replaces one of the plurality of suction units which is other than those on two ends, and discharges air outwardly in the widthwise direction of the sheet under conveyance. One of the plurality of suction units which is other than those on the two ends and the discharge unit can be mounted selectively on at least one support member. The intake source, air exhaust system, and switching device supply suction air to the suction unit when the suction unit is mounted on the support member, and supply discharge air to the discharge unit when the discharge unit is mounted on the support member.

BACKGROUND OF THE INVENTION

The present invention relates to a delivery device in a sheet-fed offsetrotary printing press, which is arranged on the upstream sheet conveydirection side of a pile board and comprises a suction unit fordecreasing a sheet convey speed.

In a sheet-fed offset rotary printing press of this type, a sheetprinted by a printing unit is conveyed as it is gripping-changed fromthe grippers of an impression cylinder to the grippers of deliverychains. After that, the sheet is released from the grippers at theconvey terminal end and drops onto a pile board to be stacked there.Since the sheet conveyed by the delivery chains is gripped by thegrippers only at its leading edge, the trailing edge of the sheet mayflutter. Also, when the sheet is released to drop, an inertia occurs asthe sheet travels, and the edge of the sheet may not be aligned whenstacked.

In order to prevent this, a plurality of suction wheels line up belowthe sheet under conveyance on the upstream sheet convey direction sideof the pile board in the widthwise direction of the sheet. The suctionwheels have suction surfaces which draw the sheet by suction in slidablecontact with it and rotate at a peripheral speed lower than the sheetconvey speed. Thus, the traveling speed of the released sheet that hasbeen gripped by the grippers is decreased. In double-sided printing, ifthe suction wheels described above are located within a pattern printedon the reverse surface of the sheet, the suction surfaces of the suctionwheels damage the image portions printed on the sheet to degrade theprinting quality. Hence, the suction wheels must be located in non-imageportions which are not printed.

If non-image portions do not exist other than the two ends of the sheetin the widthwise direction or the number of non-image portions is small,the number of suction wheels is limited, and the center of the sheetbecomes slack between the suction wheels, that is, so-called middleslack occurs. When such middle slack occurs, the two ends of the sheetmay be disengaged from the suction wheels and are not drawn by them bysuction, so the sheet convey speed cannot be sufficiently decreased. Asa result, the sheet flutters. When the sheet is stacked, the edge of thesheet is not aligned well, and comes into contact with the brackets ofthe suction wheels to damage the printing surface.

In order to solve this, an apparatus is proposed as shown in JapanesePatent Laid-Open No. 2000-95409, which comprises a plurality of suctionwheels which are arranged in the widthwise direction of a sheet to beconveyed, and at least a pair of nozzles which are arranged below thesheet on the two sides of the sheet to sandwich the center of the sheetin the widthwise direction. The pair of nozzles discharge air to blowupward the sheet under conveyance. In this apparatus, the air dischargedirections from the nozzles are directed outwardly in the widthwisedirection of the sheet to correct the middle slack, in which the sheetbecomes slack downward, by an air layer formed by air from the nozzles.Thus, the two ends of the sheet are not disengaged from the suctionwheels.

In the delivery device in the conventional sheet-fed offset rotaryprinting press, to prevent the middle slack of the sheet, the nozzlesare additionally arranged in addition to the suction wheels. Thisincreases the number of components. Also, in addition to a hose tocommunicate suction air to the suction wheels, a hose to supplydischarge air to the nozzles is also required. This makes the structurecomplicated to increase the manufacturing cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a delivery device ina sheet-fed offset rotary printing press, in which a structure toprevent middle slack of a sheet-type object to be delivered issimplified to decrease the manufacturing cost.

In order to achieve the above object, according to the presentinvention, there is provided a delivery device in a sheet-fed offsetrotary printing press, comprising a plurality of suction units which arearranged above a pile board on an upstream sheet convey direction sidebelow a sheet under conveyance in a widthwise direction of the sheet andwhich draw by suction the sheet under conveyance in slidable contacttherewith, at least one discharge unit which replaces one of theplurality of suction units which is other than those on two ends andwhich discharges air outwardly in the widthwise direction of the sheetunder conveyance, at least one support member on which one of theplurality of suction units which is other than those on the two ends andthe discharge unit can be mounted selectively, and air switching meansfor supplying suction air to the suction unit when the suction unit ismounted on the support member and supplying discharge air to thedischarge means when the discharge means is mounted on the supportmember.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view schematically showing a delivery device in asheet-fed offset rotary printing press according to an embodiment of thepresent invention;

FIG. 2 is a plan view of the delivery device shown in FIG. 1;

FIG. 3 is a front view showing the main part of the delivery deviceshown in FIG. 1;

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 2;

FIG. 5 is a view seen from the arrow V of FIG. 2;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is a perspective view of an air blowing box to be mounted on thedelivery device shown in FIG. 1;

FIG. 8 is a sectional view showing a state wherein the air blowing boxis mounted on a support member;

FIGS. 9A and 9B are plan and front views, respectively, of the main partshowing a state wherein air blowing boxes are mounted on the deliverydevice shown in FIG. 1; and

FIG. 10 is a view for explaining switching between an air intake/exhaustsource and a suction unit/discharge unit in the delivery device shown inFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A delivery device for a sheet-fed offset rotary printing press accordingto an embodiment of the present invention will be described withreference to FIGS. 1 to 10.

Referring to FIG. 1, a delivery device 1 for a sheet-fed offset rotaryprinting press comprises a pair of delivery frames 2 which oppose eachother at a predetermined gap. The delivery frames 2 axially support apair of sprockets 3. A pair of delivery chains 4 are looped between thepair of sprockets 3 of the delivery frames 2 and a pair of printingunit-side sprockets (not shown). A plurality of sets of gripper units 5(schematically shown in FIG. 1) comprising grippers and gripper padsline up on each of gripper bars supported between the pair of deliverychains 4 at predetermined intervals. After printing, a sheet 6 which isgripped by the gripper units 5 and conveyed as the delivery chains 4travel is released from the gripper units 5 and drops on the upstreamsheet convey direction side of the sprockets 3.

A pile board 7 with four corners suspended by four elevating chains 8moves vertically when a motor (not shown) rotatesclockwise/counterclockwise. A flat rectangular parallelepiped pallet 9having a hole where the forks of a fork lift or the like can be insertedis placed on the pile board 7. On the upstream sheet convey direction (adirection of an arrow B) side of the pile board 7, five suction units10A to 10E comprising suction wheels arranged below the sheet 6 underconveyance line up in the widthwise direction (directions of arrows Cand D) of the sheet 6 under conveyance, i.e., in a directionperpendicular to the convey direction (directions of an arrow A and thearrow B) of the sheet 6, as shown in FIG. 3. A sheet lay 11 abutsagainst the leading edge of the dropping sheet 6 to align it.

As shown in FIG. 2, a pair of subframes 13A and 13B are arranged tooppose each other at a predetermined gap in the directions of the arrowsC and D, and two stays 14 and 15 horizontally extend between thesubframes 13A and 13B. A driving shaft 16 is rotatably supported betweenthe subframes 13A and 13B and rotatably driven by a motor (not shown).One subframe 13B and a support stay 18 which is attached between thestays 14 and 15 rotatably support screw shafts 17A and 17B. The screwshafts 17A and 17B extend toward the other subframe 13A with their axialmovement being regulated. When the projecting portions of the screwshafts 17A and 17B through the subframe 13B are manually rotatedclockwise and counterclockwise, the suction units 10A, 10B, 10D, and 10Eand discharge units 80A and 80C (to be described later) move in thedirections of the arrows C and D.

The screw shafts 17A and 17B which support support members 25A, 25B,25D, and 25E to be movable in the sheet widthwise direction arelongitudinal feed inverse helical screws and each have a screw pitchthat is larger on the outer side than on the inner side. A supportmember 25C which is located at the center has no threaded portion anddoes not move accordingly. Hence, the gap between a discharge unit 80and suction unit 10 in the widthwise direction of the sheet 6 underconveyance is adjusted in accordance with the size of the sheet 6.

A rotating shaft 19 is rotatably supported between the pair of subframes13A and 13B. When a motor (not shown) rotatably drives the rotatingshaft 19 clockwise/counterclockwise, the subframes 13A and 13B move inthe directions of the arrows A and B with respect to the pair ofdelivery frames 2 through pinions 20 and racks (not shown) axiallymounted on the two ends of the rotating shaft 19. A sheet lay 21 whichabuts against the trailing edge of the sheet 6 dropping onto the pileboard 7 to align it has a large number of air vent holes 21 a and isattached to the stay 14 to extend in the directions of the arrows C andD.

As shown in FIG. 3, blocks 22 a each having one end supported by thestay 14 about a corresponding small shaft 23 as the swing centerswingably support corresponding detection pieces 22 which detect theupward movement limit of the pile board 7. When the pallet 9 of the pileboard 7 that has moved upward abuts against the detection pieces 22, thedetection pieces 22 detect the pallet 9 to stop upward movement of thepile board 7. This prevents the pallet 9 from pushing up the suctionunits 10 or the like.

The suction units 10A to 10E and the support members 25A to 25E whichsupport them will be described with reference to FIGS. 4 to 6. Thesuction units 10A to 10E and the support members 25A to 25E have thesame basic structure. Hence, only the suction unit 10E and supportmember 25E will be described hereinafter, and the remaining suctionunits 10A to 10D and support members 25A to 25D will be described whennecessary.

As shown in FIG. 4, the stays 14 and 15 support the flat block-likesupport member 25E to be movable in the widthwise direction (thedirections of the arrows C and D) of the sheet 6 under conveyance. Ascrew hole 28 is threadably formed in an inclined upper mount surface 27of the support member 25E. A flat block-like support target member 26Ewhich forms the suction unit 10E is mounted on the inclined upper mountsurface 27 of the support member 25E. The support target member 26E hasa vertically extending insertion hole 29. A lower surface 30 of thesupport target member 26E is brought into contact with the mount surface27 of the support member 25E. After that, a bolt 31 (engaging member)inserted in the insertion hole 29 is threadably engaged in the screwhole 28 (engaging target portion) to mount the support target member 26Eon the support member 25E.

As shown in FIG. 6, the support member 25E has a large-diameter throughhole 32 and two small-diameter through holes 33 (one through hole 33 isnot shown). The diameter of the through hole 32 is larger than thediameter of the driving shaft 16 and incorporates a bearing 34. A sleeve35 is fitted on the driving shaft 16. The sleeve 35 is rotatablysupported in the through hole 32 of the support member 25E through thebearing 34. Fastening a set screw 36 allows to rotate the sleeve 35together with the driving shaft 16. A ring-like slide member 38A fittedon the driving shaft 16 and one end face of the sleeve 35 sandwich adriving gear 37. The driving gear 37 is mounted on one end face of thesleeve 35 with bolts.

A coming-out preventive member 40 is mounted on the other end of thesleeve 35 with a set screw. The coming-out preventive member 40 and astep 35 a formed on the sleeve 35 sandwich the support member 25E. Thus,when the support member 25E moves in the directions of the arrows C andD, the sleeve 35 moves together with the support member 25E. A slidemember 38B fitted on the driving shaft 16 is mounted on the outersurface of the coming-out preventive member 40.

A substantially cylindrical moving element 42 having a threaded portion42 a to threadably engage with the screw shaft 17B is fitted in thethrough hole 33 of the support member 25E. A ring member 43 axiallymounted on one end of the moving element 42 and a step 42 b of themoving element 42 sandwich the support member 25E. When the movingelement 42 moves in the directions of the arrows C and D, the supportmember 25E also moves together with the moving element 42 in thedirections of the arrows C and D. As shown in FIG. 5, a moving element44 having the same function as that of the moving element 42 threadablyengages with the other screw shaft 17A. When the screw shafts 17A and17B are rotated, the support member 25E moves together with the screwshafts 17A and 17B in the directions of the arrows C and D through themoving elements 42 and 44. As shown in FIG. 4, the support member 25Ehas an air passage 45 which extends between an upper end opening 45 a inits upper surface and a lower end opening 45 b in its side surface. Ahose joint 46 is attached to the lower end opening 45 b.

As shown in FIG. 6, a large-diameter pulley 52 is rotatably supported bya shaft 50, which extends upright on a support target member 26, througha bearing 51. A gear 54 is rotatably supported at the distal end of theshaft 50 through a bearing 53. The gear 54 is mounted on the upper endface of the large-diameter pulley 52 through bolts. A bolt 56 whichthreadably engages with the shaft 50 through a washer 55 regulates thegear 54 from coming out from the large-diameter pulley 52 and shaft 50.

As shown in FIG. 5, small-diameter pulleys 62 and 63 are rotatablysupported by shafts 60 and 61, which extend upright in the upper portionof the support target member 26, through bearings. Coming-out preventivemembers 64 and 65 regulate the small-diameter pulleys 62 and 63 fromcoming out from the shafts 60 and 61. A suction belt 66 having a largenumber of suction ports 66 a in its outer surface is looped among thesmall-diameter pulleys 62 and 63 and large-diameter pulley 52 to form atriangle.

As shown in FIG. 5, an air duct 67 is arranged between thesmall-diameter pulleys 62 and 63 to oppose the inner side of the suctionbelt 66. The air duct 67 has a U-shaped section such that its upperportion that opposes the suction belt 66 is open. When suction air froman intake source 101 (to be described later) is supplied to the air duct67, that portion 66b of the suction belt 66 which opposes the air duct67 forms a suction surface which draws by suction the sheet 6 underconveyance in slidable contact with it. An air passage 68 is formedunder the air duct 67. The air passage 68 vertically extends through thesupport target member 26 so an upper end opening 68 a and lower endopening 68 b communicate with each other. The upper end opening 68 a ofthe air passage 68 is connected to a communication hole 67 a formed inthe bottom of the air duct 67.

As described above, when the support target member 26E is mounted on thesupport member 25E, the upper end opening 45 a of the air passage 45comes into contact with the lower end opening 68 b of the air passage68, so the air passage 45 of the support member 25E communicates withthe air passage 68 of the support target member 26E, as shown in FIG. 4.Simultaneously, the driving gear 37 of the support member 25E mesheswith the gear 54 of the support target member 26E.

As shown in FIG. 5, a belt 70 which guides the sheet 6 gripped andconveyed by the gripper units 5 is arranged below the delivery chains 4.The belt 70 is looped among a driven roller 71, a driving roller (notshown), and a tension roller (not shown), and travels at the same speedas that of the delivery chains 4.

The air blowing boxes 80A and 80C and an air blowing box 80B (dischargeunits) will be described with reference to FIGS. 7 and 8. As the threeair blowing boxes 80A to 80C have the same basic structure, only the airblowing box 80C will be described, and the remaining air blowing boxes80A and 80B will be described properly when necessary.

As shown in FIG. 7, the air blowing box 80C comprises a base 81 having atrapezoidal section in the directions of the arrows A and B and a hollowbody 82 mounted on the base 81. The hollow body 82 is formed thin andelongated in the directions of the arrows C and D and has a hollowportion 83 in it. As shown in FIG. 8, the base 81 has an air passage 84with an upper end which communicates with the hollow portion 83 of thehollow body 82 through a window 82 a and a lower end which is connectedto a lower end opening 84 a, and an insertion hole 85 in which the bolt31 (engaging member) is to be inserted. A lower surface 86 of the base81 is brought into contact with the mount surface 27 of the supportmember 25E, and the bolt 31 inserted in the insertion hole 85 isthreadably engaged in the screw hole 28 (engaging target portion) of thesupport member 25E, to mount the base 81 on the support member 25E.

The hollow body 82 has five air blowing ports 87B and a large number ofsmall-diameter discharge ports 88. The air blowing ports 87B blow airoutwardly (the direction of the arrow D) in the widthwise direction ofthe sheet 6 under conveyance. The discharge ports 88 discharge airupward. A pair of screw holes 89 are formed in the front surface in thedirection of the arrow A of the hollow body 82. As shown in FIG. 8, aguide member 90 having an arcuate section is attached to the frontsurface of the hollow body 82. The guide member 90 is formed of a thinplate and has a bent portion 90 a, at its one end, which is formed bybending. The bent portion 90 a is attached to the hollow body 82 withbolts 91 threadably engaging in the screw holes 89 of the hollow body82. The lower end of the guide member 90 extends downward toward thesheet lay 21.

The air blowing boxes 80B and 80C are different from the air blowing box80A described above in the direction of air discharged from air blowingports 87. More specifically, as shown in FIGS. 9A and 9B, five airblowing ports 87A formed in the air blowing box 80A are directed in thedirection of the arrow C. The five air blowing ports 87B formed in theair blowing box 80C are directed in the direction of the arrow D. Theair blowing box 80B has four air blowing ports, i.e., air blowing ports87A and 87B. Of the four air blowing ports, the two air blowing ports87A close to the air blowing box 80A are directed in the direction ofthe arrow C, and the remaining two air blowing ports 87B close to theair blowing box 80C are directed in the direction of the arrow D.

Five air supply devices 100A to 100E shown in FIG. 10 supply dischargeair or suction air to the respective support members 25A to 25E. The airsupply devices 100A to 100E share the one air intake source 101 whichsupplies suction air to the suction units 10A to 10E through therespective support members 25A to 25E. The air supply devices 100A to100E also share one air exhaust source 102 which supplies discharge airto the air blowing boxes 80A to 80C through the support members 25A to25E. The air intake source 101 and air exhaust source 102 are shared bythe air supply devices 100A to 100E.

The air intake source 101 and air exhaust source 102 are connected tothe air supply devices 100A to 100E through a switching device 103. Theswitching device 103 comprises an air intake passage 105 which isconnected to the intake source 101 through a hose 104, an air blowingpassage 107 which is connected to the air exhaust source 102 through ahose 106, an air supply passage 109 which is connected to the hose joint46 through a common hose 108, and a switching valve 110 whichselectively changes over the air passage 109 between the air passages105 and 107.

The switching valve 110 has a notch 110 a with a semilunar section. Whenthe notch 110 a is at the position indicated by an alternate long andtwo short dashed line in FIG. 10, the air passage 105 and air passage109 communicate with each other through the notch 110 a. When the notch110 a is at a position indicated by a solid line where it has beenpivoted from the position indicated by the alternate long and two shortdashed line by substantially 90°, the air passage 107 and air passage109 communicate with each other through the notch 110 a. An L-shapedlever 111 is swingably supported at its center about a shaft 112.extending upright from an apparatus fixing portion as the swing center.A manipulation lever 113 is attached to one end of the lever 111, andone end of a connection bar 114 is pivotally mounted on the other end ofthe lever 111. A switching bar 115 is provided to the switching valve110. The distal end of the switching bar 115 is pivotally mounted on theother end of the connection bar 114.

Delivery operation in the delivery device having the above arrangementwill be described. First, a case will be described when the convey speedof the sheet delivered by the suction units 10A to 10E is to bedecreased. In this case, the support target members 26 are mounted onthe mount surfaces 27 of the support members 25A to 25E of all thesuction units 10A to 10E with the bolts 31, as shown in FIG. 4. In thisstate, the manipulation levers 113 of all the air supply devices 100A to100E are pivoted counterclockwise, as indicated by the alternate longand two short dashed line in FIG. 10, to allow the air passages 105 andair passages 109 to communicate with each other.

Thus, suction air is supplied to the air passages 45 of the supportmembers 25A to 25E of all the suction units 10A to 10E, and to the airpassages 68 of support target members 26A to 26D and of the supporttarget member 26E which communicate with the corresponding air passages45. The suction air supplied to the air passages 68 is then supplied tothe air ducts 67, so the sheet 6 under conveyance is drawn by suction bythe suction surfaces 66 b of the suction belts 66 which oppose the airducts 67.

Referring to FIG. 6, when the driving shaft 16 is driven by the motor(not shown) to rotate, the sleeves 35 of the support members 25A to 25Erotate. As the sleeves 35 rotate, the driving gears 37 rotate togetherwith them to rotate the gears 54 of the support target members 26A to26E meshing with the driving gears 37. Thus, the large-diameter pulleys52 rotate together with the gears 54, so the suction belts 66 loopedamong the corresponding large-diameter pulleys 52 and small-diameterpulleys 62 and 63 travel in the direction of the arrow A at a speedslightly lower than the convey speed of the sheet 6. At this time, thebelts 70 (FIG. 5) are driven by motors (not shown) to travel in thedirection of the arrow A at substantially the same speed as thetraveling speed of the delivery chains 4.

The sheet 6 which is released from the gripper units 5 to drop at theconvey terminal end of the delivery device 1 is drawn by suction at itstrailing edge by the suction surfaces 66 b of the five suction belts 66to be in slidable contact with them. Thus, the traveling speed of thesheet 6 is decreased, so the sheet 6 is stacked on the pallet 9 on thepile board 7.

A case will be described wherein the delivery device is to be shiftedfrom single-sided printing to double-sided and the conditions of thenon-image portions are not met. More specifically, assume that thenumber of non-image portions is limited and non-image portions are notprovided at the center in the widthwise direction of the sheet 6, oreven if they are provided, their widths are narrow. In such a case, thethree suction units 10B, 10C, and 10D cannot be arranged to be locatedat the center in the widthwise direction of the sheet 6 underconveyance. In this case, the air blowing boxes 80A, 80B, and 80C areprovided in place of the suction units 10B, 10C, and 10D.

First, the bolts 31 that mount the support target members 26B, 26C, and26D are loosened, and the suction units 10B, 10C, and 10D are removedtogether with the support target members 26B, 26C, and 26D from thesupport members 25B, 25C, and 25D. Subsequently, the air blowing boxes80A, 80B, and 80C are mounted on the support members 25B, 25C, and 25Dwith the bolts 31.

In this state, the manipulation levers 113 of the air supply devices100A and 100E are pivoted counterclockwise, as indicated by thealternate long and two short dashed line in FIG. 10, to allow the airintake passages 105 and air supply passages 109 to communicate with eachother. Thus, suction air is supplied to the suction units 10A and 10E tosupply the suction air to the suction belts 66 of the suction units 10Aand 10E, respectively. Simultaneously, the manipulation levers 113 ofthe air supply devices 10B, 100C, and 100D are pivoted clockwise asindicated by the solid line in FIG. 10, to allow the air passages 107and air passages 109 to communicate with each other.

Thus, discharge air is supplied to the air passages 45 of the supportmembers 25B, 25C, and 25D, and to the air passages 84 of the air blowingboxes 80A, 80B, and 80C that communicate with the air passages 45. Thedischarge air supplied to the respective air passages 84 is dischargedfrom the air blowing ports 87A and 87B and discharge ports 88 of the airblowing boxes 80A, 80B, and 80C. When the driving shaft 16 is driven torotate by the motor (not shown), the suction belts 66 of the suctionunits 10A and 10E mounted on the support members 25A and 25E travel inthe direction of the arrow A at a speed slightly lower than the conveyspeed of the sheet 6.

When delivery operation is performed in this state, air discharged fromthe air blowing ports 87A and 87B of the three air blowing boxes 80A,80B, and 80C, which are arranged under the sheet 6 released from thegripper units 5 to drop at the convey terminal end of the deliverydevice 1, forms an air layer that flows outwardly in the widthwisedirection of the sheet 6. This air layer conveys the sheet 6 to slightlyfloat from the air blowing boxes 80A, 80B, and 80C. This prevents middleslack of the sheet 6, and the two ends of the sheet 6 will not disengagefrom the suction belts 66 of the suction units 10A and 10E, so that theconvey speed of the sheet 6 can be decreased sufficiently. As a result,fluttering of the sheet 6 is prevented reliably, and misalignment of theedge of the sheet when stacked can be prevented, and the sheet can beprevented from coming into contact with the brackets of the suctionwheels, so its printing surface will not be damaged.

Air is discharged from the discharge ports 88 of the air blowing boxes80A, 80B, and 80C toward the lower surface of the sheet 6 underconveyance to float the sheet 6. Thus, middle slack of the sheet 6 canbe prevented reliably. The trailing edge of the sheet 6, which is drawnby suction with the suction units 10A and 10E to decrease the conveyspeed, is guided to the sheet lay 21 by the guide members 90. Thus, thesheet 6 is stacked on the pallet 9 smoothly and reliably.

According to this embodiment, the suction units 10B to 10D and airblowing boxes 80A to 80C can be selectively mounted on the supportmembers 25B to 25D. No discharge units need be provided in advanceindependently of the suction units, thus simplifying the structure. Boththe mounting structures of the suction units 10B to 10D with respect tothe support members 25B to 25D and the mounting structures of thedischarge units 80A to 80C with respect to the support members 25B to25D employ the bolts 31. Thus, two types of mounting structures are notneeded, so the structure can be simplified and the number of componentscan be decreased.

The switching device 103 is provided which switches air supply from theair intake source 101/air exhaust source 102 to the suction unit10/discharge unit 80. Thus, air can be supplied to the suction unit 10and discharge unit 80 with the common hose 108, so the structure can besimplified and the number of components can be decreased.

In this embodiment, the three discharge units 80A to 80C are provided.Alternatively, the central unit may employ a suction unit, and the pairof units on the two sides may employ discharge units. Of the threedischarge units 80A to 80C, the central unit may employ a dischargeunit, and the units on the two sides may employ suction units. The sizesof the air blowing boxes 80A to 80C in the longitudinal direction may beadjustable in accordance with the sheet size. The sheet suffices as faras it is a sheet-type object.

As has been described above, according to the present invention, thesuction units and discharge units can be selectively mounted on thesupport members. No discharge units need be provided in advanceindependently of the suction units, so the structure can be simplified.Two types of mounting structures are not separately needed for thesuction units and discharge units, so the structure can be simplifiedand the number of components can be decreased. Common pipes allowcommunication of air between the suction units and discharge units tosimplify the structure and decrease the manufacturing cost.

1. A delivery device in a sheet-fed offset rotary printing press,comprising: a plurality of suction units which are arranged above a pileboard on an upstream sheet convey direction side below a sheet underconveyance in a widthwise direction of the sheet and which draw bysuction the sheet under conveyance in slidable contact therewith; atleast one discharge unit which replaces one of said plurality of suctionunits which is other than those on two ends and which discharges airoutwardly in the widthwise direction of the sheet under conveyance; atleast one support member on which said one of said plurality of suctionunits which is other than those on the two ends and said discharge unitcan be mounted selectively; and air switching means for supplyingsuction air to said suction unit when said suction unit is mounted onsaid support member and supplying discharge air to said discharge meanswhen said discharge means is mounted on said support member.
 2. A deviceaccording to claim 1, further comprising a mounting structure with whichsaid one of said plurality of suction units which is other than those onthe two ends and said discharge unit are commonly mounted on saidsupport member.
 3. A device according to claim 2, wherein said mountingstructure comprises an engaging target portion provided to said supportmember and an engaging member to engage with said engaging targetmember, said engaging member serving to engage with said engaging targetportion to selectively fix said one of said plurality of suction unitswhich is other than those on the two ends and said discharge unit tosaid support member.
 4. A device according to claim 3, wherein saidengaging target portion comprises a screw hole formed in said supportmember, and said engaging member comprises a bolt which is to bethreadably engaged in said screw hole through an insertion hole formedin said one of said plurality of suction units which is other than thoseon the two ends and said discharge unit.
 5. A device according to claim1, wherein said air switching means comprises an air intake source whichsupplies suction air to said suction unit, an air exhaust source whichsupplies discharge air to said discharge unit, and a switching valvewhich switches a first air passage connected to said suctionunit/discharge unit between a second air passage connected to said airintake source and a third air passage connected to said air exhaustsource.
 6. A device according to claim 1, wherein said air switchingmeans is provided to correspond to said one of said plurality of suctionunits which is other than those on the two ends.
 7. A device accordingto claim 6, further comprising a manipulation portion which switchessaid air switching means when said one of said plurality of suctionunits which is other than those on the two ends is replaced by saiddischarge unit.
 8. A device according to claim 1, wherein said dischargeunit which is arranged at a portion other than a center in the sheetwidthwise direction comprises a plurality of air blowing ports whichblow air from a center of the sheet under conveyance toward one end inthe sheet widthwise direction.
 9. A device according to claim 1, whereinsaid discharge unit which is arranged at a center in the sheet widthwisedirection comprises a plurality of air blowing ports which blow air froma center of the sheet under conveyance toward the two ends in the sheetwidthwise direction.
 10. A device according to claim 1, wherein saiddischarge unit comprises a plurality of discharge ports which dischargeair substantially perpendicularly toward a lower surface of the sheetunder conveyance.
 11. A device according to claim 1, wherein each ofsaid suction units comprises a suction wheel.
 12. A device according toclaim 11, wherein said suction wheel comprises a belt type suctionwheel.
 13. A device according to claim 1, wherein each of said suctionunits includes a suction surface which draws by suction the sheet underconveyance to be in slidable contact therewith.
 14. A device accordingto claim 1, further comprising a first driving member which is providedto said support member, and a second driving member which is provided toeach of said suction units and is connected to said first drivingmember, wherein each of said suction unit comprises suction means whichis rotatably driven by said second driving member, and when said firstdriving member is driven with each of said suction units being mountedon said support member, said suction means rotates through said seconddriving member.
 15. A device according to claim 1, wherein said supportmember comprises a screw hole and first opening which are common betweeneach of said suction units and said discharge unit, each of said suctionunits comprises a first insertion port and second opening whichcorrespond to said screw hole and first opening of said support member,and said discharge unit comprises a second insertion port and thirdopening which correspond to said screw hole and first opening of saidsupport member.
 16. A device according to claim 1, wherein said supportmember comprises a plurality of support members arranged in thewidthwise direction of the sheet, and said plurality of support membersselectively support said suction unit/discharge unit.
 17. A deviceaccording to claim 1, further comprising a screw shaft which issupported by a frame and supports said support member to be movable inthe widthwise direction of the sheet, wherein when said screw shaft isoperated, said support member is moved in accordance with a sheet size.